In pursuit of high-efficiency, environmentally friendly energy production, solid oxide fuel cell (SOFC) technologies have emerged as a potential alternative to conventional turbine and combustion engines. SOFCs are generally defined as a type of fuel cell in which the electrolyte is a solid metal oxide (generally non-porous or limited to closed porosity), in which O2− ions are transported from the cathode to the anode. Fuel cell technologies, and particularly SOFCs, typically have a higher efficiency and have lower CO and NOx emissions than traditional combustion engines. In addition, fuel cell technologies tend to be quiet and vibration-free. Solid oxide fuel cells have an advantage over other fuel cell varieties. For example, SOFCs can use fuel sources, such as natural gas, propane, methanol, kerosene, and diesel, among others, because SOFCs operate at sufficiently high operating temperatures to allow for internal fuel reformation. However, challenges exist in reducing the cost of SOFC systems to be competitive with combustion engines and other fuel cell technologies. These challenges include lowering the cost of materials, improving degradation or life cycle, and improving operation characteristics, such as current and power density.
Among the many challenges with the manufacture of SOFCs, the formation of free standing and fully integrated SOFC stacks parameters remains a notable engineering hurdle, particularly, SOFC stacks utilizing a series electrical connection, or SOFC stacks utilizing a variety of different materials with different processing. In this respect, prior art techniques have focused on processing individual component layers or a plurality of layers having similar processing parameters combined with a final joining process to bond all of the components to form a SOFC stack. The final joining process usually involves bonding the individual layers or cells together using a solder or glass encapsulant and entails multiple firing cycles. Often the layers and the cells are merely clamped together and held under pressure. In view of the foregoing, the industry continues to have a need for improved SOFC cells and SOFC cell stacks.